The Geological Features. 153 



hood furnishes numerous examples of the violent 

 nature of these agencies, and the part they played in 

 the configuration of the surrounding country as we 

 now see it. 



The greater part of the South of Scotland belongs 

 to the Lower Silurian system, the earlier beds of this 

 series of rocks forming the range of the Moorfoot Hills, 

 which border the southern extremity of the region we 

 propose including in our sketch of the geology of the 

 Craigmillar district. This system may be fairly taken 

 as representing the backbone on which the upper 

 groups of later deposits rest ; and from these beds of 

 the Lower Silurian we will ask the reader to accom- 

 pany us while we endeavour to explain the different 

 and successive measures as they occur — taking them 

 up, as far as possible, in their geological sequence. 



Following this range in a westerly direction, the 

 Lower Silurian of the Moorfoots abuts against the 

 Pentlands, giving place to the upper members of the 

 same system, these again being surmounted by the 

 sandstones and grits of the Old Red Sandstone form- 

 ing this part of the Pentlands. The Pentlands them- 



